Air conditioning-steam jet system



Jan. 19, 1965 A. E. STANFORD 3,165,906

AIR CONDITIONING-STEAM JET SYSTEM Filed May 15, 1963 I N l0 61 N 3 F o (\I g 8 .D E o O O 3 2 .O 2

Alfred E. Stanford Inventor Patent Attorney United States Patent 3,165,906 am CGNDHTIGNING-STEAM JET SYSTEM Alfred E. Stanford, Glen Rock, Ni, assignor to Esso Research and Engineering Company, a corporation of Delaware Filed May 15, 1963, Ser. No. 280,695

2 Claims. (Cl. 62--2o8) The present invention is concerned with an integrated marine steam jet/air-conditioning system. In particular, it relates to a water evaporation air conditioning system integrated within a marine steam turbine condensate system.

Since World War II, a trend has been established toward the air conditioning of merchant vessels. This was a direct result of the wholesale acceptance of air conditioning ashore in all its possible commercial, recreational and habitational variations. The early trend in the marine field was directed exclusively towards the air conditioning of passenger accommodations. The reasons for this were purely economical, the paying passengers began to demand the same type of comfort afloat as they were used to getting in hotels, restaurants and theaters.

However, owners of cargo vessels began to recognize the benefits of air conditioning aboard non-passenger ships. Generally, these benefits were derived from improving the crews living conditions, thereby lowering absenteeism, reducing labor turnover and generally improving production and moral. In particular, the adoption of air conditioning has been particularly concentrated in oil tankers since these ships spend a good part of their time traveling in and out of tropical and semi-tropical waters where the oil producing countries are generally found. In the vast tanker building program and cargo vessel replacement program that has been going on for the past several years, the air conditioning of crews quarters has been given considerable attention and virtually all these vessels are now being air conditioned.

The present method for converting normal ventilation systems into air conditioning systems requires the installation of a great deal of additional equipment. In the first place, refrigeration units must be introduced which usual 1y are too large to be included within existing working space. Therefore, it has been foundnecessary to build additional rooms onto the decks of the vessel or else to convert much needed storage space for this purpose.

Secondly, these refrigeration units utilize inert gas, e.g. Freon12, cooling systems which require electrically operated compressors to function. This imposes a tremendous load on the available electrical power on the ship. Therefore, it has been found necessary to install additional turbogenerator electrical capacity in order to provide the extra power.

The introduction of air conditioning into cargo vessels is therefore seen to have involved a large capital expenditure in the form of the specialized refrigeration equipment introduced, the additional electrical power geueraitng equipment needed and also in the extensive special adjustments necessary on the superstructure in order to provide the necessary space for the new equipment.

It is therefore an object of the present invention to pro vide a marine air conditioning system which does not require a complicated and expensive refrigeration unit. A further object is to provide a marine air conditioning system which can operate without the introduction of additional power generating equipment. A still further object is to provide a marine air conditioning system which can be conveniently fitted into normal working space on vessels.

It has now been unexpectedly found that present steam turbine power plane systems aboard vessels could be used, with only relatively small modifications and additions to neared Jan. 19., 1965 np I provide the cold water necessary for air conditioning the vessels. This can be achieved by integrating a steam ejector water evaporation cooling unit into the main steam turbine condensing system which is present in all turbine operated vessels. The cold water produced in the cooling unit is then' circulated to cooling coils located in the existing ventilation system. Here the water picks up heat from the air, and the resulting cooled air is then passed throughout the area desired to be air conditioned by means of blowers. V The energy requirements for this integrated cooling system consist only of the steam necessary to operate the ejectors and the electricity necessary to operate the cold water pump which circulates the refrigerated water to the cooling coils. The steam is readily available-by tapping otf some of the vessels main steam supply piping. This will not appreciably affect the operating efliciency of the turbines as the amount of steam needed by the steam ejectors will be quite small compared to the overall turbine steam supply. Also the electrical load added is well within the capabilities of the reserve power of almost all electrical generating system now in use. 7

The invention can be fully understood by referring to the following description and claims taken in conjunction with the accompanying drawing.

Referring now to the figure, a diagrammatic representationof an integrated marine steam jet-water evaporation air conditioning system is shown. In a specific embodiment of the invention as described herewith, the vessel in question has the following physical characteristics:

A. Overall length 690'0" B. Breadth 90'0" C. Deadweight capacity tons 35,550 D. Max. rated shaft horsepower at 103.2

rev. 17,600 E. Normal shaft horsepower at 100 rev. 16,000 F. Speed knots 17 G. Capacity of cargo oil tanks at 100%' full cu. ft 1,722,000

Steam, shunted from the turbine supply, is introduced 123456 123456 7890 7890 123456 at a pressure of about 850 pounds per square inch (-p.s.i.g.) into line -11. Reduction valve 12 converts this high pressure steam into steam having a pressure of 145 to 150 p.s.i.g. The lower pressure steam is passed by line 13 to manifold 14 where the steam is distributed to various steam consuming elements within the integrated system. Line 15 carries steam from manifold '14 to steam ejector 16. The rate of steam flow is maintained at about 1695.

' lbs/hr. by means of valve -17. Ejector 16 draws avacuum in evaporator 18 by means of vacuum line 43 which serves to flash off water vapor in that unit. It is desired that the vacuum in the evaporator be maintained at about 0.18 to 0.40, e.g., 0.36 inch of Hg absolute. This will correspond to a water temperature of about 45 to 55 l-'-., e.g. 50 F. The figure depicts an embodiment of the integrated system wherein two separate ejector systems, i.e., a and b, are used. It should be noted that the number of ejectors used will depend on several variables in the system, namely the capacity of the ejector used, the amount of cooled water needed, the temperature of the water entering the evaporator, etc. Therefore, the number of ejectors depicted here should not be considered as limiting the scope of the invention in any way. Furthermore, .the ejector may be of the one stage or two stage types.

The exhaust ejector steam containing added water vapor picked up in the ejector is passed to the main turbine condenser 1 9 by means of line 20. The rate of exhaust flow is about 2000 lbs/hr. This exhaust stream will have a temperature of about 118 -F. as it enters the main condenser 19.

A vacuum of about 2.5 inches Hg absolute or 63.5 mm. Hg is maintained in the main condenser -by the action of main air ejector 21. Line 22 carries steam at a rate of 60 lbs/hr. from manifold '14 through valve 27 to ejector 21. Cooling Water for main condenser 19 is drawn from the sea by means of main saltwater circulation pump 23 and line 24. The temperature of this water will vary, of course, depending on the season and the location of the water the vessel is traversing. In tropical climate, the water can be as warm at 95 F. The system, however, can still efiiciently utilize this water for cooling purposes. The cooling water is introduced into the main condenser at a rate of about 1060-1080 gallons/minute. It isdesirable that main condenser 19 be a two pass unit having a total of 5610 tubes or 2805 tubes per pass. The total condensing surfiace of such a preferred condenser embodiment is about 218,400 square feet. Exhaust condenser water leaves the unit by means of line 25 at a temperature of about 104 (if the inlet temperature is taken'to be about 95 F. as above) and is returned to the sea.

The total condensate in the main condenser is transported by line 32 to main condensate pump 33. The majority of water pumped here is returned by line 34 to the ships main condensate system (not shown) for recycling through the steam generating plant. The remainder of the water is used to provide the make up water for evaporator 18 by means of line 35. In the particular embodiment shown, the rate of flow of water to the evaporator is about 2 gallons/minute. This make up water enters evaporator *18 at a temperature of 110 F. but is cooled to 50 F. by the low pressure flash off of water vapor. Chilled water at 50 F. from evaporator 18 is carried to cold Water circulation pump 37 by line 36. This pump produces a flow rate of 310 gallons/minute of cold water which is led to the air cooling system by line 38. In one embodiment, three cooling coils 39, 40 and 41 are utilized to air condition the desired parts of the ship. Of course, :fewer or greater numbers of cooling coils maybe utilized depending upon the specific cooling problem involved in each vessel. Furthermore the rate of flow of cold water may be adjusted through each cooling coil to be proportional to the heat load it must carry.

Exhaust water from the cooling coils is collected in line 42 and is returned to evaporator 18. This exhaust water will be at a temperature of-about 57 Generally, the cooling coils can be installed in existing 'forced air ventilation systems aboard cargo vessels. Therefore circulation of the cooled air presents no additional problems. The condition of the rooms subjected to air conditioning by the present system is summarized below:

Dry Bulb, Wet Bulb, F. F.

Outside 95 82 Inside 85 71 Relative nuliilifiii sm.

Li, Of course, numerous other ways of modifying the above integrated system will suggest themselves to those skilled in the art. The physical constants given for the system are intended only to describe a particular embodiment of .the invention and of course will change as the subject vessel is changed. Adaptation of the above embodiment to suit any particular set of conditions is well Within the province of engineers skilled in the art.

Summarily, the present invention offers the following advantages over systems heretofore known in the art:

(1) Present vessels can utilize the integrated system within working space already available.

(2) Comparatively simple and inexpensive equipment is needed.

(3) No additional power sources are needed.

(4) N 0 additional condensers or condenser cooling water systems beyond those already existing in steam turbine power plants are required,

Having set forth the invention, that which is claimed is set forth in the appended claims.

What is claimed is:

. 1. An integrated marine steam jet/ air conditioning system comprising in combination: 7

(a) a source of high pressure steam having a value of about to p.s.i.g.;

(b) a steam ejector nozzle operatively connected to said steam source, said ejector having a vacuum outlet;

(0) an evaporation chamber having a vacuum inlet connected with said ejector vacuum outlet and additionally having a first water inlet, a second water inlet and a water outlet;

(d) a marine steam turbine condenser adapted to re ceive exhaust steam from said steam ejector and further being adapted to provide steam condensate to said first water inlet of said evaporation chamber wherein said condenser is a two pass type and is maintained at a vacuum of about 2.5 inches Hg absolute;

(e) an air cooling system having an inlet end and an outlet end, said inlet end being operatively connected to said evaporation chamber water outlet and said outlet end being operatively connected to said evaporation chamber second water inlet, whereby cooled water from said evaporation chamber is circulated through said air cooling system and returned to said evaporation chamber.

2. The system of claim 1 wherein said evaporation chamber is maintained at a vacuum in the range of about 0.18 to 0.40 inch Hg absolute.

Stalcup Jan. 25, 1938 Sampson Sept, 12, 1950 

1. AN INTEGRATED MARINE STEAM JET/AIR CONDITIONING SYSTEM COMPRISING IN COMBINATION: (A) A SOURCE OF HIGH PRESSURE STEAM HAVING A VALUE OF ABOUT 145 TO 150 P.S.I.G., (B) A STEAM EJECTOR NOZZLE OPERATIVELY CONNECTED TO SAID STEAM SOURCE, SAID EJECTOR HAVING A VACUUM OUTLET (C) AN EVAPORATION CHAMBER HAVING A VACUUM INLET CONNECTED WITH SAID EJECTOR VACUUM AND ADDITIONALLY HAVING A FIRST WATER INLET, A SECOND WATER INLET AN A WATER OUTLET; (D) A MARINE STEAM TURBINE CONDENSER ADAPTED TO RECEIVE EXHAUST STEAM FROM SAID STEAM EJECTOR AND FURTHER BEING ADAPTED TO PROVIDE STEAM CONDENSATE TO SAID FIRST WATER INLET OF SAID EVAPORATION CHAMBER WHEREIN SAID CONDENSER IS A TWO PASS TYPE AND IS MAINTAINED AT A VACUUM OF ABOUT 2.5 INCHES HG ABSOLUTE; (E) AN AIR COOLING SYSTEM HAVING AN INLET END AND AN OUTLET END, SAID INLET END BEING OPERATIVELY CONNECTED TO SAID EVAPORATION CHAMBER WATER OUTLET AND SAID OUTLET END BEING OPERATIVELY CONNECTED TO SAID EVAPORATION CHAMBER SECOND WATER INLET, WHEREBY COOLED WATER FROM SAID EVAPORATION CHAMBER IS CIRCULATED THROUGH SAID AIR COOLING SYSTEM AND RETURNED TO SAID EVAPORATION CHAMBER. 